1. Field of the Invention
The present invention relates generally to valving devices for use in beverage dispensing systems, particularly those systems for drawing liquids, such as beer, from containers, such as beer kegs or barrels, using a gas to drive the liquid from the container. More particularly the present invention relates to an improved coupler for positive interconnection with the fluid container valve system for tapping the valve system to draw liquid from the container.
2. Discussion of the Prior Art
In systems for tapping keys of fluid and particularly containers of beer there has been used a valve assembly secured to the top of the keg for providing access to the fluid ultimately to be delivered from the keg to a remote position for distribution. Typically, the valve assembly includes a dual valve arrangement with a siphon tube which extends from the valve assembly to the bottom of the keg. The valve assembly is fixed within the keg neck or other valve receiving member to provide a valved access to the fluid once it is pressurized. The valve system, when tapped by a coupler or some other keg tapping means connected to a pressure source, allows pressurized gas to flow into the keg until the desired pressure within the keg is achieved to force the fluid out of the keg through the valve system and ultimately to a distribution device where the fluid can be used to fill glasses and the like. The valve system is one which allows the pressurized gas, usually carbon dioxide, to be forced out of the keg to distribution device until the keg is entirely emptied of fluid.
With regard to the coupler or other tapping mechanism, such mechanisms are typically inserted by rotation into the valve assembly. Then by separate action, the handle is actuated to open the valves and permit the flow of fluid into and out of the keg in the appropriate channel. After the fluid has been completely dispensed from the keg, the reverse sequence is followed to reseal the valves. If the aforementioned sequence is followed, there will be no loss of fluid or gas in the tapping or untapping procedure.
However, if the handle is inadvertently placed in the tapped or valve open position prior to attaching the coupler to the valve assembly, the valves will be moved to an open position before the coupler is fully in place allowing some leakage to occur until the coupler is rotated sufficiently to seal the interface between the coupler and valve assembly. Similarly, if the handle is not relocated to close the valves prior to untapping, leakage will occur until the coupler is rotated out of the valve assembly to a position where the valves reach their naturally closed position. Particularly where the keg contains toxic or otherwise dangerous fluid, the leakage occurring from failure to follow the correct tapping and untapping procedure constitutes a physical danger to the operator. For example, where the keg contains concentrated agricultural chemicals, such as pesticides, insecticides, fertilizer, etc., leakage of these chemicals through an improper coupling technique can be seriously deleterious to the health of the operator.
One of the most effective systems ever devised to overcome the drawbacks of the prior art is described in U.S. Pat. Nos. 4,159,102 and 4,181,143. Broadly stated, the systems described in these patents provided better sealability between movable parts to prevent unnecessary leakage, safe operability to protect the operator even from his own errors, and constructional features facilitating cleaning operations and economic savings in manufacturing and assembly, among others. These systems use a coupler device which has a coupler body provided with a wedge surface which is helical in configuration circumscribing the bottom of the coupler body. The wedge surface is adapted to engage inwardly protruding lugs formed on the valve assembly. With this construction, upon rotation of the coupler into the valve system, the interaction of the wedge surfaces with the lugs forces the coupler body downwardly within the valve assembly and into a sealing relationship therewith.
The thrust of the present invention is directed toward providing an improved coupler assembly which has certain cost and operational advantages over the coupler arrangement described in the aforementioned patents. For example, as will be apparent from the description which follows, the coupler assembly of the present invention is placed over, rather than into, the valve system and is positively secured to the outside surfaces of the keg neck or valve assembly receiving member. This permits the coupler to be more compact, avoids the necessity of forming the complex wedge surfaces on the coupler body, and enables the improved seal with the valve system to be accomplished. The problems inherent in forming the wedge surface engaging ears on the valve system and the propensity of these ears to possibly bend or break in operation is also uniquely avoided. Additionally, the coupler of the present invention is also provided with a highly novel and very effective safety locking mechanism which precludes removal of the coupler from the valve system so long as the valves are in an open position.
Another aspect of the present invention concerns the provision of an improved valve system wherein the siphon tube extends proximate the bottom of the beverage container and one of the springs which operates one of the valves is housed interiorly of the siphon tube with one end thereof in pressural engagement with the bottom of the container.